The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A typical diesel engine in a motor vehicle is calibrated to meet emissions standards, power and torque requirements, and to meet fuel economy targets. Once those targets are met, the engine is then calibrated to account for sound radiated from the engine. However, by first calibrating for emissions, power, torque and fuel economy targets, the engine may have high combustion pressures and high pressure rise rates within the combustion cylinder. These pressures and rise rates can act as a dynamic forcing function on the structure of the diesel engine. This in turn can lead to the diesel engine radiating high noise levels, possibly exceeding the engine noise objectives. In addition, these high noise levels can be in excess of typical gasoline powered engine noise levels and can be aurally displeasing to the operator and passengers within the motor vehicle.
Therefore, it is desirable to calibrate diesel engines by considering engine sound requirements during the calibration process. Accordingly, the present invention seeks to provide the art with a method of calibrating the engine utilizing the combustion noise of the cylinder to meet engine radiated noise and sound quality objectives.